重度单纯性肥胖儿童外周血中NPY和胰岛素水平的测定

目的　了解神经肽 Y(NPY)与肥胖的关系。方法　应用放免法测定重度单纯性肥胖儿童和正常体重儿童外周血中 NPY和胰岛素含量。结果　肥胖组血浆 NPY含量 (1 85.97± 35.86pg/ml)较对照组 (1 53.57± 42 .0 5pg/ml)显著升高。肥胖组血胰岛素含量也显著高于对照组。结论　肥胖症的发生可能与高水平的血 NPY有关。     

Neuropeptide Y system in the retina: From localization to function

The retina is a highly complex structure where several types of cells communicate through countless different molecules to codify visual information. Each type of cells plays unique roles in the retina, presenting a singular expression of neurotransmitters. Some neurotransmitter systems in the retina are well understood, while others need to be better explored to unravel the intricate signaling system involved. Neuropeptide Y (NPY), a 36 amino acid peptide, is one of the most common peptide neurotransmitter in the CNS and a highly conserved peptide among species. We review the localization of NPY and NPY receptors (mainly NPY Y₁, Y₂, Y₄ and Y₅) in retinal cells. Common features of the expression of NPY and NPY receptors in mammalian and non-mammalian species indicate universal roles of this system in the retina. In the present review, we highlight the putative roles of NPY receptor activation in the retina, discussing, in particular, their involvement in retinal development, neurotransmitter release modulation, neuroprotection, microglia and Muller cells function, retinal pigmented epithelium changes, retinal endothelial physiology and proliferation of retinal progenitor cells. Further studies are needed to confirm that targeting the NPY system might be a potential therapeutic strategy for retinal degenerative diseases.     

The effects of enalapril and losartan on mechanical ventilation–induced sympathoadrenal activation and oxidative stress in rats

Background

Mechanical ventilation (MV) is a method of maintaining appropriate gas exchange in patients who are unable to sustain adequate alveolar ventilation. While lifesaving in the short-term, prolonged MV leads to altered cardiovascular responses and enhanced lung injury, but the exact mechanism is unknown. Therefore, we investigated the involvement of the sympathoadrenergic and renin–angiotensin system in MV-induced altered cardiovascular responses.

Methods

Sprague–Dawley rats were divided into six groups: (1) spontaneous breathing (SB); (2) SB + enalapril (100 μg/kg intravenous infusion); (3) SB + losartan (100 μg/kg infusion); (4) 12 h of MV; (5) MV + enalapril; and (6) MV + losartan. After the animals were sacrificed, blood and tissue samples were collected. Tyrosine hydroxylase, dopamine beta hydroxylase, and neuropeptide Y were measured in adrenal medulla and hypothalamus, whereas AT1 was measured in lung tissues by Western blot. Norepinephrine enzyme-linked immunosorbent assay and total antioxidant capacity were assayed in plasma.

Results

Our findings indicated that MV increases the sympathetic activation markers in adrenal medulla and hypothalamus. Moreover, oxidative stress was increased in lung and brain tissues. Treatment with enalapril or losartan reduced the lipid peroxidation in lung and brain tissues, while preserving the tissue glutathione content and plasma antioxidant capacity.

Conclusions

These data demonstrate that the inhibition of the renin–angiotensin system by enalapril or losartan may reduce the MV-induced increase in sympathetic activity markers and oxidative stress, and thus, may have a beneficial effect as adjuvant therapy.     

Neuropeptide Y increases intracellular calcium in rat pinealocytes

The pineal gland is mainly innervated by sympathetic fibres containing noradrenaline (NA) and neuropeptide Y (NPY). NA released at night stimulates melatonin synthesis via a beta1-adrenergic-induced increase in cyclic adenosine monophosphate (cAMP) concentration potentiated by an alpha1-adrenergic-induced increase in Ca2+ concentration. We previously showed that NPY acted on presynaptic Y2 receptors inhibiting NA release and on postsynaptic Y1 receptors stimulating melatonin synthesis. Here we used Fura-2 imaging to assess the effect of NPY on the intracellular Ca2+ concentration, [Ca2+]i, in cultured rat pineal cells. In 84% of cells, on average, 10 nM NPY induced a progressive rise of [Ca2+]i from its basal value of 102+/-3 nM to a plateau of 180+/-6 nM (n = 467 cells), which lasted the time of NPY application. This effect of NPY appeared dependent on extracellular Ca2+.     

犬肺栓塞模型血浆NPY、CGRP和尿TXB2、6-keto-PG1α的变化

目的建立犬自体血栓肺栓塞模型,研究其血浆NPY、CGRP和尿TXB2、6-keto-PG1α与急性肺栓塞的关系.方法14只健康杂种犬随机分为栓塞组和对照组,每组各7只.分别注射自体血栓(0.04 g/kg)混悬液20 ml和生理盐水20 ml.记录注栓前、注栓后0.5、1、2、4、6 h各时点血流动力学指标和动脉血气,同时采血、留尿标本检测相关实验指标.结果栓塞组注栓后PO2较注栓前和对照组明显降低;栓塞组注栓后MPAP较注栓前和对照组明显升高,而CI注栓后则明显下降.栓塞组注栓后血浆NPY从基线逐渐上升,4 h达高峰,而血浆CGRP从基线逐渐下降,6 h达最低点.肺动脉血浆AT-Ⅱ注栓后上升,4 h达高峰.栓塞组血浆和尿TXB2均在1 h达高峰,此后逐渐下降,两者变化具有一致性;血浆和尿6-keto-PGF1α注栓后0.5 h内即达高峰,此后下降,两者变化趋势具有一致性.结论血管活性物质NPY、CGRP和AT-Ⅱ参与PTE的病理生理过程;PTE的肺血流动力学异常与TXA2、PGI2的失衡有关;尿TXB2和6-keto-PGF1α可作为监测体内TXA2和PGI2的变化的指标.     

不同程度的持续规律运动训练对大鼠摄食及体重的影响

目的：探讨轻中度规律体力运动与过度体力运动对大鼠摄食，体重的变化及对血中瘦素（1eptin）和NPY的影响。方法：21只大鼠连续做程度不同的无负重游泳训练，按照训练程度不同分为对照组（N组）、适量运动组（GE组）及疲劳运动组（EE组）。观察训练期间3组大鼠的摄食量及体重变化；5周后，检测各组大鼠的小肠推进率，血清、血浆中NPY及leptin水平。结果：运动5周后GE组与N组比较摄食量显著增多，但体重无明显下降，血清leptin水平下降伴血浆NPY水平升高；EE组与N组及GE组比较，摄食量显著减少，体重明显减轻，血清leptin水平下降伴NPY水平下降，小肠推进率明显升高。结论：适量运动可以增进食欲而不引起体重的增加，且不伴有小肠排空加速；长期疲劳运动可以导致肠道平滑肌紊乱，小肠排空加速，并打破下丘脑对摄食-能耗平衡调节的维持，使机体能量处于负摄人状态。     

Coordinated seasonal regulation of metabolic and reproductive hypothalamic peptides in the desert jerboa

Jerboa (Jaculus orientalis) is a semi‐desert rodent displaying strong seasonal variations in biological functions in order to survive harsh conditions. When environmental conditions become unfavorable in early autumn, it shuts down its reproductive axis, increases its body weight, and finally hibernates. In spring, the jerboa displays opposite regulations, with a reactivation of reproduction and reduction in body weight. This study investigated how genes coding for different hypothalamic peptides involved in the central control of reproduction (Rfrp and Kiss1) and energy homeostasis (Pomc, Npy, and Somatostatin) are regulated according to seasons in male jerboas captured in the wild in spring or autumn. Remarkably, a coordinated increase in the mRNA level of Rfrp in the dorso/ventromedial hypothalamus and Kiss1, Pomc, and Somatostatin in the arcuate nucleus was observed in jerboas captured in spring as compared to autumn animals. Only Npy gene expression in the arcuate nucleus displayed no significant variations between the two seasons. These variations appear in line with the jerboa's seasonal physiology, since the spring increase in Rfrp and Kiss1 expression might be related to sexual reactivation, while the spring increase in genes encoding anorexigenic peptides, POMC, and somatostatin may account for the reduced body weight reported at this time of the year. J. Comp. Neurol. 524:3717–3728, 2016. © 2016 Wiley Periodicals, Inc.     

白癜风皮损中NPY VIP和SP的研究

目的 探讨NPY（神经肽Y）、VIP（血管活性肠肽）、SP（神经肽P物质）在白癜风发病机制中的作用。方法 采用SABC免疫组化法对20例白癜风患者（活动期10例，稳定期10例）的皮损、非皮损区以及10例正常人皮肤中的NPY、VIP和SP进行研究，并测定各组皮肤标本中NPY、VIP及SP的免疫反应性。结果 活动期白癜风皮损中NPY、VIP及SP的免疫反应性明显增强，与正常对照及未受累皮肤比较差异有差异性，NPY与SP的反应在白癜风活动期皮损与稳定期皮损比较差异也有显著性。VIP的免疫反应性在白癜风活动期皮损与稳定期皮损中相比稍增强，但差异无统计学意义。结论 神经多肽与白癜风的发病有关，尤其与白癜风的活动性有关。NPY和SP可能在白癜风的发病机制中也起一定的作用。     

Associations between the human growth hormone-releasing hormone- and neuropeptide-Y-immunoreactive systems in the human diencephalon: a possible morphological substrate of the impact of stress on growth

Previous studies revealed that stress is a pivotal factor in the regulation of growth. Psychological harassment may result in psychosocial dwarfism with delayed puberty, short stature and depression. Growth hormone (GH) secretion is suppressed by stress, possibly via the attenuation of growth hormone-releasing hormone (GHRH) secretion. However, the morphological substrate of this phenomenon has not been elucidated yet. Since neuropeptide Y (NPY) levels in the plasma is increased by administration of various stressors, the common consensus is that NPY plays a crucial role in the stress response. In the present study, we examined the putative juxtapositions between the NPY- and GHRH-immunoreactive (IR) systems in the human hypothalamus using double-label immunohistochemistry. Our findings revealed that the majority of the GHRH-IR perikarya formed intimate associations with NPY-IR fiber varicosities. The majority of these juxtapositions were found in the infundibular nucleus/median eminence where NPY-IR fiber varicosities often covered a significant surface area of the GHRH neurons. Since the juxtapositions between the GHRH-IR perikarya and NPY-IR fiber varicosities may be functional synapses, they may represent the morphological substrate of stress-suppressed GH secretion. The large number of contacting elements indicates that NPY plays a pivotal role in GH release, and may be considered as a major factor in the attenuation of growth by stress in humans.